Cold hardiness & minimum temperature

Is Pinguicula cyclosecta (Pinguicula cyclosecta)cold hardy? Hardiness zone & min temp

Also called Cyclosecta Butterwort, Purple-leaf Butterwort.

More about pinguicula cyclosecta

About Pinguicula cyclosecta

Pinguicula cyclosecta · also called Cyclosecta Butterwort, Purple-leaf Butterwort · houseplant

Pinguicula cyclosecta is a compact Mexican butterwort famed for its near-circular, purple-flushed leaves arranged in a tidy rosette that glistens with insect-trapping mucilage. A reliable beginner carnivore, it wants bright light, pure water and a gritty mineral mix, retreating into tiny silvery succulent winter leaves before lifting violet flowers in spring.

Cold limit: USDA 9-11 (indoor/greenhouse in most regions) · RHS H2 (13-27°C)

Watch for — Winter rosette rot: The small silvery winter leaves rot in wet medium. Reduce watering drastically once the plant enters dormancy and improve air circulation.

What pinguicula cyclosecta's hardiness rating actually means

Pinguicula cyclosecta is half-hardy (RHS H2). It survives a mild winter outdoors in a sheltered spot, but a hard frost kills it — so in colder zones it is lifted, potted, or grown as a tender plant. Its RHS rating of H2 means: Tender — survives a frost-free greenhouse or a very mild, sheltered spot. On the US scale that maps to USDA 9-11 (indoor/greenhouse in most regions) — the zones where it can be left outdoors year-round.

New to these scales? The USDA hardiness zone map explained covers how the zone numbers work, and you can find your own zone with the zone finder.

Minimum temperature — and what happens below it

Minimum survivable temperature is roughly about 1 to 5 °C — tolerates cold but no real frost. Pinguicula cyclosecta shrugs off cold nights but a real, sustained freeze will kill it.

Concretely, for pinguicula cyclosecta as it gets too cold:

Down to roughly about 1 to 5 °C it copes, especially if dry and sheltered.
A sustained hard frost collapses the top growth; whether it returns depends on whether the roots, crown or tubers froze.
Wet cold is far more lethal than dry cold for this plant — soggy, frozen soil is the usual killer.

Can pinguicula cyclosecta go outside or overwinter — and where?

It can live outside year-round only in the mildest, most sheltered part of USDA 9-11 (indoor/greenhouse in most regions) or a frost-free UK microclimate.
In colder zones, grow it in a pot you can move under cover, or lift its tubers/roots and store them frost-free over winter.
A south-facing wall, free-draining soil and a dry winter position can push it a full zone hardier than the books suggest.

Work back from your local frost dates with the frost-date calculator: the last spring frost and first autumn frost are what really decide when pinguicula cyclosecta can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H2 figure above.

Frost protection for borderline pinguicula cyclosecta

Pinguicula cyclosecta is right on a hardiness edge in many gardens, so if you are pushing it, these measures buy it the margin it needs:

Mulch the crown or root zone deeply with bark, straw or leaf-mould before the first hard frost.
Move container plants against a warm wall or into an unheated but frost-free porch or greenhouse.
Fleece the top growth on the coldest nights, and keep it on the dry side — dry roots survive cold far better than wet ones.
Lift dahlia-type tubers or tender crowns after the first light frost blackens the foliage and store them somewhere cool but frost-free.

Pinguicula cyclosecta hardiness — frequently asked questions

Is pinguicula cyclosecta cold hardy?

Pinguicula cyclosecta is half-hardy (RHS H2). It survives a mild winter outdoors in a sheltered spot, but a hard frost kills it — so in colder zones it is lifted, potted, or grown as a tender plant. Borderline outdoors. In its mild end of USDA 9-11 (indoor/greenhouse in most regions) (and sheltered UK gardens) pinguicula cyclosecta can stay out; in colder areas it must be lifted, brought in, or treated as a frost-tender plant.

What is the minimum temperature pinguicula cyclosecta can survive?

Minimum survivable temperature is roughly about 1 to 5 °C — tolerates cold but no real frost. Pinguicula cyclosecta shrugs off cold nights but a real, sustained freeze will kill it.

What hardiness zone is pinguicula cyclosecta?

Pinguicula cyclosecta is rated USDA 9-11 (indoor/greenhouse in most regions) and RHS H2 — Tender — survives a frost-free greenhouse or a very mild, sheltered spot.

Can pinguicula cyclosecta survive winter outside?

It can live outside year-round only in the mildest, most sheltered part of USDA 9-11 (indoor/greenhouse in most regions) or a frost-free UK microclimate. In colder zones, grow it in a pot you can move under cover, or lift its tubers/roots and store them frost-free over winter. A south-facing wall, free-draining soil and a dry winter position can push it a full zone hardier than the books suggest.

How do I protect pinguicula cyclosecta from frost?

Mulch the crown or root zone deeply with bark, straw or leaf-mould before the first hard frost. Move container plants against a warm wall or into an unheated but frost-free porch or greenhouse. Fleece the top growth on the coldest nights, and keep it on the dry side — dry roots survive cold far better than wet ones. Lift dahlia-type tubers or tender crowns after the first light frost blackens the foliage and store them somewhere cool but frost-free.